Continuous process of manufacturing metal tubes.



M. B. LLOYD. CONTINUOUS PROCESS OF MANUFACTURING METAL TUBES.

14 SHEETS-SHEET 1.

[NVENTOR APPLICATION FILED JULY 12, 1911. 1,027,864. Patented May 28,1912.

WITNESSES:

I M. B. LLOYD.

. CONTINUOUS PROCESS OF MANUFACTURING METAL TUBES.

' APPLICATION FILED JULY 12, 1911. 1,027,864. Patented May 28, 1912.

14 SHEETS-SHEET 2.

' INVENTOR M. B. LLOYD. CONTINUOUS PROCESS OF MANUFACTURING METAL TUBES.

v APPLICATION FILED JULY 12, 1911. 1,027,864. Patented May 28, 1912.

l4 SHEETS-SHEET 3.

mum

WITNESSES M. B. LLOYD.- GONTINUOUS PROCESS OF MANUFACTURING METAL TUBES.

I APPLIUATION FILED JULY 12, 1911. v I LOQZQM. v Patented May 28, 1912.

14 BHEETSSHEET 4.

WITNESSES I [/VVE/V T018 M. B. LLOYD. CONTINUOUS PROGESS OFMANUFACTURING METAL TUBES.

2 l 9 l 00 2 W M d .w w M P APPLICATION FILED JULY 12 1911. 1,027,864.,

14 SHEETS-SHEET 5.

[NVE/VTOR WITNESSES M. B. LLOYD.

conmmous mocnss OF MANUFACTURING METAL TUBES.

APPLICATION I ILED JULYlZ, 1911. 1,027,864! 4 4 Patented May 28 1912.

14 SHEETS-SHEET 6.

WITNESSES M. B. LLOYD.

CONTINUOUS PROCESS OF MANUPAGTUBING'METAL TUBES.

Patentd Ma 28, 1912.

14 SHEETS-SHEET 7.

APPLICATION FILED JULY 12, 1911.

WITNESSES: 8 [NVENYOR Y m. B. LLOYD.

- CONTINUOUS PROCESS OF MANUFACTURING METAL TUBES.

v APPLIOA 1,027,864. 'IIOH FILED JULY12 1911 PatentedsMay 28}, 1912- 14flKBETS-SHEET a.

d f 7 6f 2 I Lf I .g )1 b 1 a L J L WITNESSES: I 10 Aflorney M. B.LLOYD. CONTINUOUS PROCESS OF MANUFACTURING METAL TUBES.

APPLICATION FILED JULY 12, 1911. ,864 PatentedMay 28, 1912.

14 SHEETS-SHEET 9.

INVENTOR M. B. LLOYD. CONTINUOUS PROCESS OF MANUFACTURING METAL TUBESAYPLIOATIOH FILED JULY 12, 1911. I 1,027,864. Patented May 28, 1912.

14 8HEBT8-BHEET 10.

o Zox I zax M. B. LLOYD. CONTINUOUS PROCESS OF MANUFACTURING METALTUBES.

APPLICATION FILED JULY 12, 1911.

1,927,864a I Patented May 28, 1912.

.rd a i N 1 M. B. LLOYD. CONTINUOUS PROCESS OF MANUFACTURING METALTUBES.

APPLICATION IILED JULY 12, 1911. 1,027,864. Patented May 28, 1912.

14 SHEETS-SHEET l2.'

WITNESSES:

INVENTOR WTNE' M. B. LLOYD.

CONTINUOUS PROCESS OF MANUFACTURING METAL TUBES.

' APPLIGATIOH FILED JULY 12 1911.

Patented May 28, 1912.

14 SHEETS-SHEET 18.

7 la; ll

M. B. LLOYD. CONTINUOUS PROCESS OF MANUFACTURING METAL TUBES.

I APPLICATION FILED JULY 12, 1911. 1,027,864.

Patented May 28, 1912.

14 SHEETS-SHEET l4.

WITNESSES UNITED sTATEs PATENT OFFICE.

mAnsHALI. B. LLOYn'OF MENOMINEE, MICHIGAN, ASSIGNOR To AUTOMATIC WELDINGCOMPANY, OF M INEE; MICHIGAN, A CORPORATION OF MIOH GAN.

Specification of Letters Patent.

CONTINUOUS PROCESS OF MANUFACTURING METAL TUBES.

Patented May 28,1912.

Application filed July 12, 1911. Serial No. 638,202.

To all whom it may coiwem Be it known that I, MARSHALL BURNS ILLOYD, acitizen of the United States, and a resldent of Menommee,Menom1neecounty,

not welded. And my invention is particularly directed to the manufactureof thin walled metal tubes of the kind used in the construction of lightvehicles, such as bicycles; as distinguished from thick walled, water,steam and gas pipes, which are-produced by processes that are notapplicable -to themanufacture of thin walled tubing.

. As compared with my hereinafter dcscribed invention, the present dayprocesses of making butt seamed and butt Welded .metal tubing, are slow,laborious and wasteful; require plants and equipments which are large,and expensive to construct, to

operate and to. maintain; and, produce tubing which is not dependablyuniform and which in length only approximates the requirements ofpurchasers.

Among the objects ofmy invention are the following: 1st. To producemetal tubes of superior quality; as to uniformity of composition; as touniformity of cross section; as to uniformity of strength;- and, as tostraightness. 2nd. To produce metal tubes without waste of material; inother words,

to produce a full unit of tubing from' every unit of flat stripstock,3rd. To produce direct from flat-strip metal stock a succession ofstraight butt seamed, or butt welded tubes of the exact length and crosssection specified by customers; 6., to perform steps of suchnature andsequence that each portion of tubing-shall be fully completed and itsspecified'lngth determined before it is severed from the parent stock;Whereb many independent steps and frequently repeated operations inpresent processe's are avoided and material, time, labor and space.

are saved. ethQ To produce s uch metal tube, at less cist than has beenpossible hithert fq in brief, to produce them with less labor, withlabor of lower grade, with less power, with less heat, with a lessexpensive plant or equipment, in less time, in less space, and, asalready stated, without waste of material. 5th. To produce, incontinuing se ries, metal tubes of several sizes from strip stock of onesize.

As more fully disclosed hereinafter, I attain these and other objectsand results by eliminating, and avoiding the necessity for, many stepscommonly performed in the manufacture of butt seamed and welded metaltubes, and by reducing to a constant every factor or step in thehandling or manipulation of the metal stock, performing the same acts,imposing the same strains, in

identical periods of time, upon every part I set a substantiallycontinuousthereof. piece of flat metal stock in motion longitudinally,and while it is in motion and without interrupting such motion I performupon itall of the acts necessary to form the flat strip into-butt seamedtubing, to weld the longitudinal seam thereof, to make and maintain itin straight condition, to reduce it to specified cross section, and

to deliver successive portions in the final form of completed tubes ofrespectively specified lengths.

My invention will be more readily under-- stood by reference to theaccompanying drawings, forming part of this specification,

and in which I have illustrated the several steps comprising my processas practiced in the machine which I find best suited to the purposes ofmyinvention,

Figure 1 is side elevation of said machine orapparatus; Fig. 2 is a planview thereof; Figs. 3, 4 and 5, together constitute-an enlarged planview of the machine; Figs. 3*, 3", 3, 3 ,3 3, and 3 are crosssectionalviews, illustrating the evolution or development of the tube, from theflat strip metal stock and its finished cross-section; Fig. 6, is anenlarged vertical, longitudinal section, showing the dies and a portionof the welding tools which I employ in my process; Fig. 6 is a verticalsection on the line 6*6 of Figs. 3 and 6;;5Eig. 7, is an enlargedvertical, longitudinal'fsection of the tools which I employ for weldingthe edges oif the stock after giving it tubular form, Iso the tools thatI use in removing the eld bur and die by which I reduce the tubingtogivenor specifiedcross section,

the .section being in. the same plane as-Fig. (3; Fig. 8, is a verticalcross section on the line SS of Figs. 3 and 7; Fig. 9, is an enlargedtransverse section on the line 99 of Fig. 4: showing the details of themechanism by which I forcibly draw and maintain the stock in constantmotion; Fig. 10

is a longitudinal, vertical section thereof on the line l010 of Fig. 4.;Fig. 11, is an enlarged sectional view similar to Fig. 9, but takenon'the line 11-11 of Fig. 4; Fig. 12 is a transverse section on the line1212 of Fig. 4 of the stock drawing mechanism and the means foroperating the samei Fig. 13 is an enlarged vertical and enlargedlongitudinal section on the line 1313 of Fig. 5, showing details of thetools which I use for measuring and cutting off the tubing in specifiedlengths as fast as it is finished; Fig. 14, is an enlarged transversevertical section, on the line 14-14 of Fig. 5; Fig. 15, is a stillfurther, enlarged sectional detail of the cut off mechanism, the sectionbeing taken on the line 1515 of Fig. 13 Fig. 16, is a similar view onthe line 16-16 of Fig. 13; Fig. 17, is an end View of the adjustablegage of the out 01f mechanism, on line 171.7 of Fig. 13; Fig. 18 is alike end view of the tube supporting arm adjacent to the gage, as seenfrom the line IlS1S of Fig. 13; Fig. 19 is a side view of the cut oftmechanism, disclosing the tube clamping parts; Fig. 20 is an enlargedplan view of the parts shown in Fig. 10.

The continuous tube mill shown in the drawings is one which I devisedfor the purpose of carrying out the herein described process. A completeunderstanding of its mechanical details may be gained by ref erence tomy companion application Serial No. (338,203. of even date herewith. Inthis presentapplication I will describe and refer to its constituentparts only to the extent. requisite to a fulldisclosure of all of thesteps, acts and operation embraced in my novel process. The process maybe carried out with various other tools and implements and is notlimited to the mill herein shown.

lnearrying out my process I make use of either hot-rolltul orcold-rolled fiat strip metal stock of a width approximating threetiniest-he diameter of the tubing to be produced. I provide this stockin the form of metal strips each of suflicient length to produce a Largenumber of tubes. In carrying on the process I weld or otherwise connectthe strips end to end in continuing series and therebv in ell'eetmaintain a continuous source of supply oi the llat strip stock. It willbe mnlerslood that the strips are of uni form cross sect ion -z'. (2.,of the same thickness and width. Having thus provided a .soulcc ofsupply of llatstrip stock I- dispose or position the end portion of thestock me straight line; This'end portion I confine or restrict atseveral points and, simultaneouslyat such pointsof confinement orrestriction, I perform the several acts or steps'by which the stock ismaintained in motion at a constant rate of speed and during such motionis subjected to forces which continuously and progressively convert itby. The process begins with the above described continuous source ofsupply of flat strip stock 1, at the point A and extends to the point J;that is, the process is continuously carried on and fully completedwithin the space between the lines or points A and J.', I prefer to usestrip stock 1, in bundle or reel form, and the constantly replenishedreel R is .shown at the left hand end of Fig. 1. The end portion of thestock which I position and maintain in a straight line as aforesaid, andwhich is operated upon at various points, is (o-extensive with thedistance between the lines A and J; but as hereinafter described, duringthe greater part of the time, the straight portion of the tion of thestock in a straight line I limit it to movement in a longitudinallystraight path by confining or laterally restricting It at approximatelythe points indicated by letters A, B, B, C, C, D, E. F, F, G and H. Iimpart constant speed longitudinal movement to the straightportion ofthe stock, and obviously to the whole of the stock, by grasping andpulling forward upon that portion of the stock which lies in thedivision F-G. By such action I exert tension upon the stock, rearwardlytoward the source of supply. In other words Iconstantly maintain undertension that portion of the stock which lies inthe division F--A andsimultaneously drive the stock forward at constant speed toward thepoint tubing with its edges in' abutment along a ing of successivelymeasured pieces or lengths; together with incidental and interme'diatesteps whereby the tension upon the stock-is maintained at crosssectional constants in all stages and warping is prevented, whichinsures the delivery of the tubing in straight, non-distorted condition.Thus at a pointadjacent the reel R, I position suitable forming tools ordies 2 and 3 and by proper use thereof I cause the flat stock' whiletraversing the space BC to gradually and in a cross sectionally equalmanner form into a tube with its edges in longitudinal abutment along astraight line. I Willhereafter refer to this step as the forming ofthetubing.

'At the point B I manipulate orcontrol the edges of the stock in suchmanner as to cause the seam to progressively form upon a line that isparallel with and directly above the axis of the tubing. This step isaccomplished by means of thetool 4 and will be hereinafter referred .toas the positioning of the seam of the tubing. As stated I confinethestock at the point C. Before it I reaches that point it assumes tubularform and to there hold the stock, I apply thereto tools which preventits lateral movement in any direction. The tools which I usually employand here show, are grooved metallic parts or rolls 5, between which Ipass the tubing. These tools are so constructed and positioned that theyleave the seam edges of the tubing exposed between them.- The stepsperformed by means of these tools 5 will be hereinafter referred to asthe positioning and holding of. the tubing against lateral movement andexposing the seam edges thereof. As will be presently explained thepositioning of' the seam andthis exposing of the seam edges have. to dowith the welding thereof. At the same time, and using the. same tools 5for the purpose, I not only practically encompass the tubing at the,point C, but also hold and press the abutting seam edges firmly togetherat, that point.

This step will be hereinafter re ferred to as holding-and pressingtogether the seam edges during the application of heat. And further,preferably with the same tools 5, I continuously chillthe tubing,maintain a low temperature circumferentially throughout the same, at apoint C, omitting the chilling effect only in the seam edges which areexposed between the tools or rolls 5. This ste will be hereinafterreferred to as the chilling of the tubing at the welding point, and thefunction of this step is to retain substantially the full strength ofthe tubing at the welding point and thus prevent the stretching ordistorting of the tubing by the heavy tension to which it is subjected.Having thus prepared the tubing for welding I apply heat at the point Cto the seam edges which are exposed at that point and I so localize orconfine the heat that but a small portion, longitudinally considered, israised .to the welding'point. This step of my process willbe hereinafterreferred to as uniting or welding the seam edges of the tubing.

Obviously as the stock is in constant forward motion, I am able to weldthe seam progressively as fast as fresh seam edges enter the zone orlocality of heat. The uniting. of the edges'by heat may be accomplishedby brazing the said edges but I do not stop with a weld of thatcharacter; instead I actually unite the edges autogenously by thesimultaneous movement, holding or positioning, lateral pressure and heatapplication here described. The tool or appliance that I prefer to usecomprises .an

oxy-acetylene gas torch G. I hold the nozzle 6 of this torch directlyabove the seam -edges which are exposed between the rolls 5 and play theintense flame directly upon -said edges at that point. The flame isdirected downwardly and rearwardly toward the approaching metal.

I carefully position the seam edges in a 7 straight line as beforeexplained and also secure the torch in fixed relation to the seam edges,to assure uniformity of effect fromthe flame. As the tubing passesforward under tension, the hot flame reduces the abutted edges of thetubing to a fused state whereupon as theyare held against warping ordistending'they necessarily flow or weld together. In closely observingthe action of the seam edges under the flame it will be found that asthe. edges approach the short, narrow and intensely hot welding flame,

they are partially heated by the corona of 1 but are nevertheless heldclosely is caused to set and the weld is completed before the unitedseam portions leave the immediate restraint or influence of the holdingor pressure effecting tools. As an incidental step I prefer to cool thehot freshly united seam edge portions directly after they pass thewelding zone, using Water the welding torch. This step will be liere-'lnafter referred to as removing the .Weld bur. j

Another of the simultaneous acts which I perform upon the stock is asfollows: The initially formed tubing comprises the transversely formedor bent flat strip and sits circumference is substantially equal to theoriginal width of the stock 1. It is rare that this corresponds to thecircumference and diameter required in the finished tubes. Furthermore Ifind that I can considerably improve the weld portion of the tubing bycircumferential compression of the tubing. Therefore after removing theweld bur, I further utilize the forward movement and tension of thestock and by means of a fixed tool or tools I circumferentially.compress and draw down the tubing to an exact given or specifieddiameter and cross-section. This is done at the point E and a tool whichI find useful comprises a die 9 of less diameter than the initialtubing. The tubing is drawn through this die 9 and obviously I "therebyaccomplish the reduction and sizing of the tubing as rapidly as it iswelded and without intermediate handling of the tub-- ing, also withoutpause in or interruption of the production of tubing. By changing orregulating the size of the die, I am able to produce various sizes oftubes from a single size of flat stock. Throughout the several stepsherein set forth I am careful to so position the several tools and touse and operate them in such manner as to maintain a cross sectionallyuniform tension in every partof the stock which lies within the divisionindicated by the vertical lines A and F. This step is important for Ithereby avoid unequal stretching. warping or distortion of the stock andresultant tubing;

in other words, I make the tubing both initially and finally straight.Through thus maintaining the tubing in straight condition in all stepsitbecomes unnecessary to the moment the stock is drawn into this di-.

which I generally use in the manufacture of tubes, requires the use of astrong powerfully actuated tool or mechanism which will not crush, maror distort the tubing and yet will be adequate to the overcoming of theobstacles and resistances offered by the metal stock itself and by theother operations thereon.

For the purpose of claspingthe tubing circumferentially and effectingcircumferentially uniform pull or tension thereon, I employ an appliance10 which is in nature of an endless belt positioned in the space FG.

This belt carries pairs of clamping jaws set I end to end thereon. Thejaws are shaped to fit the tubing and each pair when closed togetherthereon practically iucloses the portion'of the tubing embraced. As willpresently appear the straight upper stretch of the belt parallels thevtubing. The jaws are limited to movement transversely toward and fromthe tubing and are carried forward in continuous series by the rotationof the belt. The jaws which at any given instant constitute the upper orworking stretch of the device are in exact alinement with the tubing.They are positively closed against the tubing and the strength of theirfrictional engagement therewith is such that in moving forward the jawsare prevented from slipping'upon the tubing and the latter is pulledordrirwn through the preceding tools or dies. Irotate the belt atconstant speed and cause the several pairs of jaws to successively closeupon the tubing to impart movement to the tubing and to openapproximately at the end of the straight stretch of the belt. Byclasping the'tubing in this manner, that is substantially the wholecircumference of the tubing, the pull or tension is equalized throughoutthe circumference of the tubing, and in consequence I am able to conductthis' step of my process without distorting or warping the straighttubing which enters this pulling device. As before remarked the claspingpressure whereby I secure frictional engagement of such strength as tomake the movement of the stock positive, is carefully regulated to avoidcrushing the tubing. In drawing the stock forward in the manner from andbeyond the drawing device.

' Without any other or intermediate steps,

and without being in any 'way stopped, the tubing is thus posltioned inreadiness for the .remaining steps of the process. I support theforwardly moving stock at convenient points as at H and I to maintain itin straight condition and define its path of movement. Near the deliveryend of the drawing device I place a cutting off tool 11.

This marks the inner end point from which I measure the tubes as theyare produced and I operate the cut off device at the in- 'stant that thegiven or specified length of tubing has been, projected beyond thispoint. I employ a measuring tool or appliance of which one part is agage 12. In the course of the process I shift this gage toward and fromsaid inner end measuring point, as required 'to determine the exactlengths of successive tubes;

As shown in the drawing, I position thechanging the distance between thetools And during this movement I sever the tubingiat said inner endmeasuring point. At

that time, I also remove the gage and if the nexttube is to be ofdifferent length, I readjust the gage for co-action with the newlypresented end of the stock. Obviously the 'tube which is severed willfall down out of i the way and will not interfere with the re-- .turnofthe cut of tool to the inner end measuring point; nor does the severedor complete tube interfere with or stop the continued forward movementof the stock.

As a precaution against distorting the tubing at the cut off point whenthe tube is sev-I cred, I prefer to momentarily circumferentially claspor clamp the tubing close to the cut off but release the-tubing at theinstant following the action of the cutoff tool. It will now be obviousthat my process is continuous; and that the operatlons upon and thestrains imposed up Thus in drawing the stock I am careful to maintain 'aconstant and .unvarymg tension and am also careful to conduct alloperationsat one rate of speed. In employing the tools by which I efiectthe progressive movement, formation and finishing of the stock, Ifixtheir positions with respect to one another and do not change thepositions. It follows that the portion of the stock between any twooperating points is constant' on each portion of the stock,,are uniformwlth the operations andstrains upon every other portion thereof.

as to quantit length and state or condition notwithstan ing-the factthat the stock is in constant forward movement. conditions theproduction of tubing may be carried on indefinitely, at a constantspeed, and the tubing produced is not only straight and therefore ofgreat commercial value as compared with the tubing of commerce, but isalso of uniform cross section, uniform strength and uniform composition.Uniformity of composition is insured by the intrinsic uniformity of theflat strip stock and bythe fact that in my process the stock is notsubjected to-ex'cessive' periods of heat or to stresses or strains whichyveaken, disrupt or alter the constitution of the stock. As each tube ismade by cutting or separating it directly from the parent stock, and aseachtube produced is of individual predeter-g mined or specified lengthand requires no further trimming or cutting, it is obvious that myprocess is conducted wholly without waste of material.

By merely altering the sizes of the finishing die and pulling jaws, I

can produce various sizes of tubing from the 1 same stock. Those who arefamiliar with the ordinary processes of manufacturing tubing will atonce perceive that many steps and operations which are inherent to theolder processes are entirely eliminated and avoided in and by my hereindescribed continuous process. In marked contrast to present dayprocesses, I am able to conduct my entire process (except the gaging ormeasuring ste )within a space little more than ten feet in length andof'less width;

Under these A and it is further apparent that my process is conductedwith tools and machinery of .a y

cost which is buta fraction of the-cost ofthe equipment for carryingoutthe-older proc- .esses. r I

To the end that every detail of'my-procj a ess, as practised with theherein sown tool s,

may be more certainly understood, I will 1 now more fully describe theconstruction and operation of these tools. and mecha-' msms. 1

In the drawings, Z represents a table or bench on,which I prefer to fixthe several tools and whereon most of the steps of the process areconducted. The construction of the forming tools or mechanism isdisclosed in Figs. 1, 2, 3, 6, 22 and 23. As indicated therein, I mayform the strip into a tube by means of two sets of forming-dies 2 and 3.The first set comprises one ormore pairs of rotary dies or rolls 2, 2,which shape the strip to semi-circular form in cross section.

These rolls "are mounted on shafts 2 and 2*, held in standards 2 andconnected by equal speedspur gears 2 and 2. The strip from the reelenters the rolls through an adjust able guide 2 which may serve as aninitial die. Onleaving the forming rolls the strip enters a stationaryformipg die 3, comprising an annular die 3* andtapered mandrel stock totightly, close together. I sometimes relieve the pulling strain on thestock bydriving the forming rolls 2, as by means of 3 in a standard 3,the mandrel being-adjfistable on the block 3. Thesleeve 3 con- .tainingthe die 3 has .a flaringor tapered receiving throat 3, which may assistin shaping the strip of metal .as-i t passes through the same. Byadjustment of the parts 3 and 3, I cause the edges-of. the

when in the rolls 2, 2; Fig. 3 shows its form at the moment that it isabout to enter the die 3; and Fig. 3 shows the form of the tube as itemerges from the die 3. The edges of the metal strip are indicated bythe character 6, throughout the drawings; and as shown in Fig. 3, theseedges are in substantial abutment when the tube leaves the forming die3, and. form the seam which is to be closed. T

To prevent the formation of a wavy seam and prepare the tubing forreception by the welding mechanism, I employ a tube-seampositioningdevice 4:, which limits the seam to a vertical plane which includes theaxis of the tubing. The tube seam positioning device 4 may be a part' ofthe forming mechanism and is one of the tools which I use in welding thetubing. As shown in Figs. 1, 3, 6 and 6, the positioner is at the throatof the die 3. It is a hardened steel cross bar 4 fixed to a collar 4:which is rotatable on the sleeve 3 A worm gearing 4 is provided forrotating the collar and cross barA The ends of the bar 4: bear on theedges of the stock, see Fig. 3 and by turningor tiltin the bar one orthe other edge of the partlally formed stock may be depressed, and inthis manner the tendency I I of the strip to creep or twist laterally orcircumferentially in the dies maybe cor rected, thereby insuring astraight seam, which by means of this device and the rolls 5, I am ableto position in the exact manner required for the welding of the seamedges.

The welding tools are best shown in Figs. 2, 3, 7 and 8. One elementofthe welding mechanism is the oxy-acetylene gas torch 6 of which 6 is theburner tip or nozzle, and 5, 5, are the holding pressing and chillingrolls. The tension on the tube tends to close the seam but these rollsinsure the desired position and condition of the tubing with respect tothe torch. Y The rolls rotate freely in contact with the'tubing. Eachroll contains a peripheral groove 5 conformed to the shape of the sideof the tubing. Referlin t6 Fig; i is a will teat. that at an occupy ahorizontal plane and that the tube passes betweenithem, and is nearlyencom- I manipulating the adjusting screws shown in Figs. 6 and 7, thetwo rolls 5may be separated or moved together as required to correctlyproportion "their pressure upon the tubing. The tops of the rolls riseabove the tubing andin eflect, form a deep groove having the tube seamedges at its bottom. The nozzle of the welding torch entersthis groovein position to direct theflame upon the seam edges at a point betweenthetwo rolls, in other words at the point where the tube is most securely:held. The-rolls are of such size that they rapidly absorb and radiatethe heat communicated to them and serve to-chill or cool all parts ofthe tube not exposed between the rolls. They may be additionally cooledwith water supplied from pipes 5 and overflowing through the ducts 5.The torch is of an approvedtype, comprising the nozzle or tip'6 'and gasconducting. pipes 6 equipped with valved nipples for the flexible gaspipes 6 that supply oxygen and acetylene from suitable sources,- (notshown). The welding torch is supported in such manner that it may bequickly adjusted to working position or moved away. 6 are bracketscarryinga normally fixed arm 6,- pivotedto which is a torch carryinglever 6 Stop shoulders 6 limit the downward movement of'the'lever. Asplit carrying block 6 contains a swivel mounting 6 for the torchproper- The-part 6 is connected to the lever 6 by a horizontal stud.This arrangement permits vertical adjustment of the torch; also rotaryadjustment of the nozzle. Accurate adjustment of the nozzle is obtainedby a spring resisted thumb screw 6 connecting the torch carrying blockto the sustaining lever 6. Metal which is vaporized by the welding flamesometimes; condenses upon the. tip of the nozzle and tends to distortthe welding flame, and to maintain a uniform flame I employ a clearingdevice, the same comprising a metal finger 6 on a spring returned lever6 pivoted at 6 see Figs. 3, 7 and 8. One of the two rolls 5 has pins 6'which strike and operate the lever 6, thereby reciprocating the finger 6across the end of the nozzle, to periodically clean it.

The bur removing tool 8 appears in Figs. 1, 2, 3 and 7, and ispreferably a planer knife, tool or blade which is rigidly held by ablock or standard that contains the reduc

